Ionis Reports Setback on DMPKRx Program for Myotonic Dystrophy

Ionis Pharmaceuticals provided an update on its recently-concluded phase 1-2 clinical trial of IONIS-DMPK-2.5Rx, an experimental compound for the treatment of type 1 myotonic dystrophy (DM1). Analysis showed mixed results from the trial.

In DM1, a mutation in the DMPK gene leads to the production of toxic RNA (genetic material made from DNA) that accumulates inside muscle and other cells. IONIS-DMPK-2.5Rx is an antisense compound, designed to reduce levels of the toxic RNA.

Overall the study provided a much better understanding of how future clinical trials and improved clinical endpoints may be used. But although results from the trial showed encouraging trends in biomarker and splicing changes, the drug did not achieve concentration levels in muscle needed for it to have an effect in treating the disease.

Following these results, Ionis has decided not to advance its IONIS-DMPK-2.5Rx program.

Moving ahead with new technology

Ionis has announced that, with partner Biogen, it is now working on new technology called LICA (Ligand-Conjugated Antisense) in an effort to increase potency for future DM1 drugs. The LICA technology enhances distribution to skeletal and heart muscle.

“Ionis and Biogen are dedicated to working on advances in a new muscle-targeting LICA chemistry to increase potency for this important patient population,” the company reported. “And we hope to advance a new, more potent drug into development.”

In addition, the company said, “We would like to thank everyone that participated in the study; patients, caregivers and physicians. We are committed to the patient community and we hope to advance a new, more potent drug into development for the DM1 community.”

For more information

If you participated in the DMPK-2.5Rx trial, be sure to speak with your physician about any questions you may have regarding your trial experience and treatment plan going forward.

MDA has supported much of the foundational research that led to understanding the underlying molecular cause of DM1 and developing antisense-based and other strategies to counteract its effects.